“Although because of the current debates taking place in Washington, it may be some of the steps we put in place move more slowly than they otherwise would have,” Obama said, “I’m confident that the U.S. will continue to move in the right direction.”

Obama was speaking at Seeds&Chips, a global food and innovation summit in Milan, Italy, where he discussed the intersection of climate change and the global food system.

Obama said that the private sector, having made the determination that clean energy is the future, would lead the way. He pointed to fuel efficiency in the auto industry as an example, saying that his administration had set aggressive standards—some of which are subject to change by the current White House. But California, the largest car market in the U.S., sets its own fuel emission standards, he noted. “Even if the rules change in Washington, there’s no U.S. automaker that can afford to produce a car that is not fuel efficient to be sold in California,” he said.

The hour is almost upon us

Obama spoke with urgency about climate change, saying that he had made the issue “a top priority because I believe of all the challenges we face, this is the one that will define the contours of this century” more than any other.

“I do not believe this planet is condemned to ever rising temperatures. I believe these are problems that were caused by man and can be solved by man,” he said, stressing the need for action. Quoting Martin Luther King Jr., he said there is such a thing as being too late, and “when it comes to climate change, the hour is almost upon us.”

Although Obama only mentioned the Trump administration once in the 90-minute session that included prepared remarks and a Q&A with his one-time senior food policy advisor Sam Kass, the current tenor in Washington clearly informed his comments. During his campaign, President Donald Trump said that he would “cancel” the U.S.’s involvement in the Paris climate accord, which Obama brokered. Trump once Tweeted that the concept of global was “created by and for the Chinese.”

Obama said that the Paris agreement “did not set high enough standards to completely solve the problem of climate change, but what it did was put together the architecture, the mechanism, where each year, each country could progressively do more to reduce carbon emission.” He said that it’s important big countries that are major emitters like the U.S. and China lead the way. “It’s going to require continuing leadership on all our parts,” he said. “No one can sit on the sidelines.”

Obama said that 99% of scientists who study climate change carefully “will tell you that the planet is getting warmer and the only real controversy is how much warmer it will get.” If the planet warms at the upper end of current projections, “it would be catastrophic,” he said. “At the low end, it will still be very disruptive.” A three-foot rise in sea level could lead to mass migration, he said. “The number of refugees that could be resulting from something like that could be unprecedented in human history,” he said. If we don’t, address these issue, we can anticipate “not only real threats to food security but increases in conflict as a consequence of scarcity.”

Getting food producers onboard

Obama highlighted the work that still needs to done in the food system to both ease its impact on the environment and feed a growing planet. “Although we’ve made real progress in becoming more efficient in the energy side, we are actually seeing a continuing increase in the emissions coming out of the agricultural sector,” he said.

In Obama’s view, one of the reasons why pressure on the food system has lagged the energy sector is that food is an emotional issue and its impact on greenhouse gas emissions has not been publicized. “People aren’t as familiar with the impact of cows and methane,” he noted—an issue that will only increase as developing nations demand more protein. (Obama noted that he is a meat eater—”I respect vegetarians, but I am not one of them,” he said.)

Key to making progress is taking into account the interests of food producers, Obama said. If you prioritize environmental concerns over their economic interests, they’ll resist, he added.

Obama said he saw major potential in personalized medicine. He pointed to allergies as an example, using one of his daughters who has a peanut allergy to illustrate the point. He said she’s now going through a process at Stanford University, where she’s being evaluated for each nut to determine the type of allergy and severity. He said her doctors can now determine protocols where if she take a little nut protein in a pill each day, slowly her allergy will be eliminated.

Since his presidency has ended, Obama said that most of his time has been spent writing his third book and building the next phase of his work—the Obama Presidential Center, which is designed to help the next generation of leadership for activism.